My 2015 MBP is still going strong and Apple support were even pretty great at helping when I did have one issue, even though they classify it as Vintage. But you're totally right, I'm really impressed by the M1 and am just holding out for the M1X to upgrade.
I use BootCamp (daily lately, since we're in lockdown and it's snowing) for gaming on Windows with an eGPU. Neither of which are supported on the M1.
I'm considering selling my eGPU and just building a gaming PC (the M3 will likely be out by the time I pull trig though :/), but it was nice to have 1 machine do it all (work + play), especially since I didn't need the eGPU to play some couch co-op games (Cuphead, Castle Crashers, very cottage-friendly!)
How was your experience? I bet it was nice just plugging in and getting all that extra power.
People held on to their 2015 15" MBPs for as long as they could because they didn't like the upgrade paths. The 16" was well received and helped fix that. The M1 laptops were incredibly well received and people are excitedly jumping on them instead of feeling forced.